Apparatus and method for acoustic/mechanical treatment of early stage acne

ABSTRACT

The apparatus includes at least two skin-contacting elements, the elements having narrow end faces and a mounting assembly for holding the elements closely adjacent to each other. A driving assembly reciprocally moves one element relative to the adjacent element(s) at a frequency that produces an action on the pores of the skin to loosen sebaceous plugs present in the pores, by permitting their ready removal from the skin.

This is a division of U.S. patent application Ser. No. 10/345,909, filedon Jan. 15, 2003.

TECHNICAL FIELD

This invention relates generally to treatment of early stage acne, andmore particularly concerns mechanical and/or acoustic devices forapplying energy to the skin in the vicinity of the early stage acnelesions i.e. the sebaceous plug.

BACKGROUND THE INVENTION

Common acne, known more specifically as acne vulgaris, is generallyregarded to be the most treated skin condition in the United States.Prompt and appropriate treatment of acne, particularly in its earlystages, is important for both resolving the early stage condition andpreventing more severe acne conditions, which have possible permanenteffects, including the possibility of severe scarring. While acne canoccur in men and women of all ages, it typically occurs in adolescentsand young adults.

The earliest evidence of acne is the formation of a sebaceous plug. Thesebaceous plug, which is formed in the individual skin pores(follicles), is typically not visible to the unassisted eye, but can beseen under a microscope or other optical lens device. It is formed whena combination of corneocytes and sebum, which are both naturalcomponents of the skin, block the pore opening, and specific colonies ofbacteria within the skin pore then expand in numbers. The plug of cellsand sebum may adhere to the wall of the skin pore, leading to materialaggregation in the pore, and subsequent widening of the pole. Thissituation may in turn result in the further accumulation of sebum andother cellular material, and the eventual possible rupture of thefollicular wall, followed by an inflammatory response and the subsequentformation of inflamed papules and inflamed pustules, typically referredto as pimples.

Existing systemic treatments of acne include oral antibiotics, retinoidsand hormonal treatments. Each of these treatments, while effective tovarious extents, has its own significant side effects and disadvantages.For instance, oral antibiotic treatment reduces the number of bacteriain the skin poles, but does not decrease the rate of sebum secretions orthe actual number of the sebaceous plugs formed. Disadvantages of thevarious treatments include various undesirable skin reactions, includingskin dryness, fluid loss and possible hair loss. Typically, all suchtreatments irritate the skin to some extent.

PRIOR ART

Prior art concerning localized treatment for acne can be classifiedgenerally as “mechanical” or “chemical.”

Mechanical methods include vacuum devices, mechanized scrub brushes andmanual loop-like instruments, such as shown in U.S. Pat. Nos. 5,624,416and 4,175,551. Use of these devices is typically site-specific andusually requires a specific technique, making, them difficult to use.Methods that use heat generated by electrical resistance or ultrasoundare also known, such as shown in U.S. Pat. No. 6,245,093. Still othermethods claim to be able to kill target micro-organisms, including thosethat cause acne, using selected frequencies of electrical current, suchas shown in U.S. Pat. No. 5,891,182.

In the beauty/skin care industry, the use of micro-abrasion is also apopular treatment for “rejuvenating” skin. However, this technique ofremoving, some layers of the cornified skin layer by abrasive materialscan cause intense irritation.

Chemical methods for acne, including topical and systemic treatments andtheir possible side effects, are listed in Tables I and II below,respectively.

TABLE I Common Topical Acne Treatments Treatment Possible Side EffectSoaps and detergents to remove Drying of skin surface (xerosis) if sebumfrom skin surface used in excess Astringents and short chain Drying ofthe skin surface and break- alcohols to remove oily materials down ofthe skin's barrier function, and water in upper epidermal areas andeventual microbial entrance into the body Antibacterial agents (e.g.benzoyl <5% penetrates into the pores, with peroxide, salicylic acid),that can the rest possibly interacting with destroy bacteria when theagent is corneocytes causing irritation and in immediate contact withthe erythmea (red skin), and contact microorganisms dermatitis

TABLE II Common Systemic Acne Treatments Treatment Possible Side EffectOral antibiotics Photosensitivity, gastrointestinal problems, andbacterial antibiotic resistance Hormonal manipulations to Increased riskof thromboembolism, control sebaceous gland size and feminization inmen, and other secretion rate by regulating undesirable effects.androgens and estrogens Retinoids, which likely change Teratogenic, andother strong the cohesiveness of follicular negative side effectsepithelial cells

With the present apparatus, conditions that lead to early stage acne areprevented and early stage acne is effectively treated by maintaining orrestoring the pore openings to an open state, to allow continuingexudation from the sebaceous gland, to encourage maintaining an aerobicstate within the pore, and to prevent the development of more severeacne conditions, without the inconvenience, side effects and otherlimitations present in existing treatments.

DISCLOSURE OF THE INVENTION

Accordingly, the invention is an apparatus or the treatment of acne,comprising: at least two contacting elements having end faces which arein substantially the same plane, wherein at least one contacting elementis a moving contacting element; a mounting assembly for holding thecontacting elements substantially adjacent to each other; and anassembly for reciprocally moving said at least one moving contactingelement relative to at least one adjacent contacting element, whereinwhen the apparatus is positioned so that the end faces of the contactingelements contact the skin, an action on the skin is produced to removesebum plugs from skin pores, permitting ready removal thereof from theskin.

The contacting elements can comprise either elements of rigid material,compliant material or rows of bristle tufts. The apparatus further canbe used for an effective cleansing treatment of skin which does not havean acne condition. Still further, the apparatus could comprise a singlemoving contact element.

Another aspect of the invention is a method for treatment of skincomprising the steps of: a first step of deforming the skin from aneutral position to a first deformed position at which point the skinhas reached approximately its elastic limit; a second step permittingthe skin to return to said neutral position; and repeating the first,second steps, within a frequency range of 20 Hz to 1 kHz, to produce anaction on the skin which results in the cleansing of the skin, includingremoval of undesired material from skin pores. The method is effectivefor acne treatment as well as general skin cleansing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a typical skin pore.

FIG. 2 is a cross-sectional view of a comedone-plugged acroinfundibulum.

FIG. 3 is a cross-sectional view of the comedone-pluggedacroinfundibulum, taken along lines 3-3 in FIG. 2.

FIG. 4 shows strain characteristics for skin for differing degrees ofapplied stress.

FIGS. 5A and 5B show the relative displacement of a single tuft ofbristles moving against the skin.

FIG. 6 is an exploded view of one embodiment of the mechanical acnetreatment device of the present invention.

FIG. 7 is a schematic view of a fixed contact element part of theapparatus of FIG. 6.

FIG. 8 is a schematic view of a movable contact element part of theapparatus of FIG. 6.

FIGS. 9A, 9B, 9C and 9D show the effect on a typical sebaceous plugpositioned within a skin pore subjected to the action of the apparatusof FIG. 6.

FIG. 10 is a schematic view of a variation of the mechanical device ofFIG. 6.

FIG. 11 is a schematic view of a fixed contact element pale of theapparatus of FIG. 10.

FIG. 12 is a schematic view of a movable contact element part of theapparatus of FIG. 10.

FIGS. 13A, 13B, 13C and 13D show the effect on a sebaceous plugpositioned in a skin pore subjected to the action of the apparatus ofFIGS. 10-12.

FIG. 14 shows a variation of the mechanical device shown in FIG. 7,wherein a compliant material is applied to the contact element surface.

FIG. 15 is a diagram showing an alternate embodiment of the presentinvention with alternately linearly movable rows of bristle tufts,surrounded by a circular row of fixed bristle tufts.

FIG. 16 is a top view of the device shown in FIG. 15.

FIG. 17 is a diagram showing a variation of the mechanical device shownin FIG. 15, in which one set of bristle tufts is fixed, and the otherset moves linearly.

FIG. 18 is a top view of the device shown in FIG. 17.

FIG. 19 is a diagram showing a further alternate embodiment of thepresent invention with alternately rotationally movable sets of bristletufts.

FIG. 20 is a top view of the mechanical device shown in FIG. 19.

FIG. 21 is a diagram showing a variation of the mechanical device shownin FIG. 16 with a single set (two rows) of rotationally moving bristletufts.

FIG. 22 is a top view of the mechanical device shown in the FIG. 21.

FIG. 23 is a schematic block diagram showing the control means forcontrolling the amplitude of motion as a function of pressure applied tothe skin.

FIG. 24 is a schematic representation of the human face showing thevarious regions of the face that differ in the degree of sebum secretionand incidence of acne lesions.

FIG. 25 is a block diagram of a timer structure useful with the presentinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a representation of a typical skin pore, including theepidermis and dermis layers of the skin. The skin pore 10, also referredto as a follicle, includes a normal hair 16 and an associated sebaceousgland 18. The sebaceous gland 18 normally produces sebum lipids. Theproduction of sebum, however, is typically not sufficient alone toresult in acne. Further, acne lesions do not occur if the sebum lipidsare free to reach the surface of the skin. However, when the skin poreor follicle becomes blocked, such as by an overproduction ofcorneocytes, or inadequate shedding of the corneocytes (as shown in FIG.2), the balance of the skin system is upset. The blocked follicles leadto the formation of closed, but non-inflamed, sebaceous plugs. Thesebaceous plug (microcomedone) 215 shown in vertical cross-section inFIG. 2 and in horizontal cross-section in FIG. 3 forms in theacroinfundibulum portion of the follicle, which is the upper portion ofthe follicle.

Following the initial formation of the sebaceous plug, if the pH andoxygen tension are within certain ranges below the closed sebaceousplug, the number of Propionibacteria acnes bacteria expands, leading toa pathogenic condition. This leads further to a sequence of actions andreactions within the follicle, including damage to the follicular wall,comprising skin layers 201, 203, 205, 207 and 209, and extrusion ofaccumulated materials into the dermis portion of the skin, resulting inan inflammatory response which leads to skin lesions and pustules.

In the present invention, the focus is on maintaining theacroinfundibulum portion of the follicle in an open state, whicheliminates the environment in which the acne bacteria can thrive withinthe follicle, and encourages establishing an aerobic state within thefollicle, while at the same time minimizing the amount of sebum that canaccumulate within the infundibulum portion of the follicle.

The basic approach of the present invention is to reopen the individualpores that may have been blocked by the plug of corneocytes 211 andsebum lipids 213 (FIG. 3). It is based on the discovery that applicationof differential motion locally to the pore opening will open a blockedpore. The opening of the pore is due to the fact that the blockingmaterials within the follicles have different physical properties thanthe wall of the infundibulum and the surrounding skin. With the presentinvention, the skin area is deformed slightly and then released to arelaxed position and then deformed slightly in the opposite directionand then again released to a relaxed position, at a specified frequency,which results in the plugs being loosened from their position in theskin pores. The loosened plugs can then be readily removed, such as bywiping or washing, permitting thereafter normal skin secretion oflipids, and consequently avoiding the consequences of more fullydeveloped acne.

FIG. 4 shows three regions of the skin's elastic modulus, i.e. theamount force (stress) required to deform the skin a given degree(strain). This curve is the result of the unique mechanical organizationof the skin. This mechanical organization can be thought of as largenumbers of loose collagen fibers connected together at randomlydistributed nodal points. The mechanical behavior of such a system isvery similar to that of a woven material such as a nylon stocking. Asthe material is stretched, the fibers are first straightened out andbecome oriented in the direction of the stress (shown in FIG. 4 regionI). A relatively small amount of stress is required to produce thislevel of strain, with a modulus of elasticity typically 5×10⁻³ N/mm².Skin is elastic over this range.

Generally at the end of region I and slightly into region II, theelasticity of the skin substantially decreases and the skin becomestaut. In reunion II, some fibers become fully aligned in the directionof the stress and then carry stress directly. Further deformation willresult in ever-increasing numbers of collagen fibers being recruited tosupport the stress. The modulus of elasticity, or stiffness, of the skinincreases rapidly as this process continues until it matches thestiffness of the collagen fibers themselves (region III). The modulus ofelasticity in this region is typically 3×10³ N/mm².

In the present invention, the desired differential motion applied to theskin should be of high enough amplitude to create pore opening forces,but low enough to minimize stretching of collagen fibers in the skin.Deformation should be limited to the area of region I and the low strainarea of region II of FIG. 4, where the collagen fibers are notsignificantly stretched. To that end, the mechanical characteristics ofthe portions of the invention that contact the skin, called thecontacting elements, and the amplitude of the moving contact elementsmust be such that the degree of stress on the skin does not exceed somevalue σ₁ thus keeping the amount of strain in the skin below the valueE₁ of FIG. 4.

A first embodiment of the present invention is shown generally in FIG.6, wherein movable skin contacting elements are located in the sameplane as stationary skin contacting elements, and the bi-directionaldifferential action is shear, i.e. the two elements move in parallel toeach other along their length. The arrangement shown includes two skincontact elements 57 and 59 and a backing/spacer plate 61.

The movable and non-movable skin contacting elements are basicallyidentical. In the embodiment shown, the individual contact elements 57and 59 are each mounted on mounting plates. The fixed contact element 57is mounted on mounting plate 58, while the oscillating contact element59 is mounted on mounting plate 60. The contact elements are narrow andsomewhat elongated and are shown in detail in FIGS. 7 and 8. In theembodiment shown, the dimensions of the contact elements are typically0.800 inches long and 0.09 inches wide. The edges of each contactelement are beveled: giving it a somewhat rounded end face, while therespective ends are also rounded, as shown in the drawings.

The mounting plate 58 for the fixed contact element is approximately1.18 inches wide. The upper corners of mounting plate 58 are both cutoff, at a 36° angle. The height of the mounting plate 58 is 1.4 inches.FIG. 8 shows the combination of contact element 59 and mounting plate 60for the oscillating contact element. Mounting plate 60 is, in theembodiment shown, substantially rectangular, with a length of 1.0 inchesand a height of 0.5 inches. The upper corners of mounting plate 60 arecut off, i.e. beveled, at an angle of 45°, while the lower corners arerounded.

Oscillating contact element 59 is mounted oil mounting plate 60 on theupper edge thereof. The upper edge of contact element 59 isapproximately 0.298 inches above the upper edge of mounting plate 60.Mounting plate 60 includes two drive openings 62-62 therethrough, sothat the mounting plate 60 and contact element 59 can be moved back andforth by a driver mechanism discussed below. In the embodiment shown,the drive holes 62 are approximately square, 0.154 inches on each side.

The oscillating contact element 59 on its mounting plate 60 and thefixed contact element 57 on its mounting plate 58 are then positionedimmediately adjacent to each other, as shown in FIG. 6. The two contactelements 57 and 59 are thus substantially in registry. The twoassemblies are held together and attached to the driver mechanism 50 bytwo connecting screws 46-46. Hence the contact elements may be removedand replaced. The oscillating contact element assembly is movable bymeans of the driver that moves it reciprocally (back and forth), suchthat the mounting plate 60 moves parallel to mounting plate 58, andcontact element 59 moves reciprocally in parallel with contact element57.

The drive assembly shown generally at 50 includes two drive buttons52-52 that move reciprocally a selected distance. These drive buttonsextend into drive openings 62-62 on the oscillating mounting plate. Theoscillating contact element in the embodiment shown has a frequencywithin the range of 20 Hz to 1 kHz, with a preferred value range of80-200 Hz. As indicated above, the action of the drive assembly movesthe mounting plate 60 parallel with mounting plate 58, so that theoscillating contact element 59 moves parallel to the length of theadjacent fixed contact element 57. In the embodiment shown, the contactelement and the mounting plates are made front stainless steel, althoughthe contact elements could also be coated with a compliant material orbe composed entirely of compliant material, such as shown at 63 in FIG.14, or the contact elements could be replaced by bristle brush tufts orthe like.

In the embodiment shown, a center-to-center distance of approximately0.125 inches results in a separation between 0.09 inches wide contactelements 57 and 59 of approximately 0.035 inches. Contact element 59moves reciprocally over a total distance in a range of 0.02 inches to0.08 inches, with a preferred value of approximately 0.040 inches(+/−0.020 inches from its neutral position to its peak position) alongcontact element 57. The surface finish of the contact elements 57 and 59is such that the skin primarily moves in contact with the contactelements. A surface roughness range of 5 to 20 microinches is effective,with a preferred value of 10 microinches. The surfaces must besufficiently rough that the motion of the contact elements istransferred to the skin with minimal or no slippage. If the surface istoo smooth, the skin could be abraded. The contact element could be anelastomer or a closed cell foam. It could be a knobby surface or evenfingers.

In operation of the embodiment of FIG. 6, the edge faces of the contactelements will be positioned lightly against the skin surface and thedevice activated by a switch. The contact element 59 begins tooscillate. The device is then moved at a slow rate across the skinsurface, for instance two centimeters per second. The device operateswith a ratio of peak amplitude to the space (distance) between adjacentskin contacting elements of typically 0.57. With that action, shearforces are applied to the skin, with sufficient amplitude to slightlydistort the skin and force open the pores, but low enough to minimizeany skin stretching.

At the above-noted frequency range, with a minimum of 20 Hz, each poreopening is deformed approximately 10 times per second. At higherfrequencies, the number of deformations per second would beproportionately greater. Alternating shear stress in the tissuesurrounding the infundibulum is produced, with the adhesion between thesebaceous plug and the infundibular wall being weakened or significantlyreduced, so that the plug is essentially loosened in the pore.

While the embodiment of FIG. 6 shows one fixed contact element and onemovable contact element, it should be recognized that a plurality offixed contact elements and oscillating contact elements could be used toprovide a wider coverage for the device. In the case of a plurality ofcontact elements, the movable multiple contact element(s) areinterdigitated with the fixed contact element(s) and are driven in aganged manner.

In addition, both contact elements can be driven, preferably in equaland opposite directions of motion with respect to each other. A peakamplitude of 0.02 inches for each of two moving elements would result ina peak amplitude of relative motion of 0.04 inch.

FIGS. 9A-9D show the action on the skin and a sebaceous plug with theshear embodiment of FIGS. 6-8. FIG. 9A shows a pore 78 blocked by asebaceous plug 79 therein. The contact elements are in a neutralposition. The movable contact element will then be moved in onedirection, in parallel with the fixed contact element, which distortsthe sebaceous plug (FIG. 9B). The movable contact element and mountingplate combination is then reversed and returns to the neutral position.This is shown in FIG. 9C. The movable contact element continues in theopposite direction, which deforms the sebaceous plug in the oppositedirection (FIG. 9D). This is accomplished at the specified frequency.While generally this “double” motion is preferred, it is possible tomove the movable contact in one direction only relative to theneutral/rest position. Continued repetitive action dislodges or releasesthe sebaceous plug from the pore walls. The device is slowly movedacross the surface of the skin, producing the above results over anentire skin area.

An alternative mechanical arrangement is shown in FIGS. 10-12. Itincludes two fixed skin contact elements 24 and 26 and an intermediateoscillating contact element 28. The configuration of the elements in thetension/compression arrangement is similar to that of the elements ofthe embodiment of FIGS. 6-8, although the “shear” action of theembodiment of FIGS. 6-8 is generally preferred. In both embodiments, thedifferential strain on the skin produced by the mechanical action issufficient to result in a breaking away of the plug from the skin, dueto the difference in elasticity between the plug material and the skin.

In the embodiment of FIGS. 10-12, the individual contact elements 24, 26and 28 are each mounted on mounting plates. The fixed contact elements24, 26 are mounted on mounting plates 30-30 (FIG. 11), while theoscillating contact element 28 is mounted on mounting plate 32 (FIG.12). The contact elements are narrow and somewhat elongated and areshown in detail in FIGS. 11 and 12. In the embodiment shown, the contactelements are typically approximately 0.800 inches long and approximately0.090 inches thick. The edges of each contact element are beveled;giving each contact element a somewhat rounded end face, while therespective ends are also rounded, as shown in the drawings. The mountingplate 30 for the fixed contact element is approximately 1.18 incheswide. The upper corners of mounting plate 30 are both cut off, at a 36°angle. The height of the contact element is somewhat less (1.25 inches)on one side of the contact element relative to the other side (1.4inches).

In the embodiment shown, the fixed contact elements 24, 26 are mountedcross-wise (perpendicular) to the mounting plate, approximately 0.5inches from one edge 34 thereof. The fixed contact elements are offsetlaterally, such that they extend approximately 0.316 inches from onesurface 36 of mounting plate 30, and approximately 0.406 inches from theopposing surface 38.

FIG. 12 shows the combination of contact element 28 and mounting plate32 for the oscillating contact element. Mounting plate 32 is, in theembodiment shown, substantially rectangular, with a length of 1.0 inchesand a height of 0.5 inches. The upper corners of mounting plate 32 arecut off, i.e. beveled, at an angle of 45°, while the lower corners arerounded.

Oscillating contact element 28 is mounted perpendicularly to mountingplate 32 on the upper edge thereof. The upper edge of contact element 28is approximately 0.298 inches above the upper edge of mounting plate 32and is offset, so that it extends approximately 0.472 inches fromsurface 40 of mounting plate 32. Mounting plate 32 includes two driveholes 42-42 therethrough; so that the mounting plate 32 and contactelement 28 can be moved back and forth by a driver mechanism discussedbelow. In the embodiment shown, the drive holes 42 are approximatelysquare, 0.154 inches on each side.

The oscillating contact element 28 on its mounting plate 32 and thefixed contact elements 24 and 26 on their mounting plates 30 are thenpositioned immediately adjacent to each other, with the two fixedcontact element assemblies being back-to-back, but reversed, as shown inFIG. 10. The three contact elements 24, 26 and 28 are thus substantiallyin registry. The three assemblies are held together and attached to thedriver by two connecting screws 46-46. The oscillating contact elementassembly is movable by means of a driver that moves it back and forth,such that the mounting plate 32 moves parallel to mounting plates 30,and contact element 28 moves alternately toward and away from contactelements 24 and 26.

A drive assembly similar to that shown at 50 in FIG. 6 includes twodrive buttons which move back and forth a selected distance. These drivebuttons connect to the drive holes 42-42 on the oscillating mountingplate 32. The oscillating contact element in the embodiment shown movesat a frequency within the range of 20 Hz to kHz, with a preferred rangeof 80-200 Hz. As indicated above, the action of the drive assembly movesthe mounting plate 32 parallel with mounting plates 30, so that theoscillating contact element 28 moves toward (or away from) one adjacentfixed contact element 24 and away from (toward) the other adjacent fixedcontact element 26.

In the embodiment shown, contact elements 24 and 26 are separated by acenter-to-center distance of approximately 0.280 inches and contactelement 28 moves reciprocally over a peak-to-peak distance ofapproximately 0.150 inches between contact elements 24 and 26. Movementbetween a neutral/rest position and a peak distance (one direction) andback to neutral is also possible. In operation of the embodiment ofFIGS. 10-12, the edge faces of the contact elements will be positionedlightly against the skin surface and the device activated by a switch.The contact element 28 begins to oscillate. The device is then moved ata slow rate across the skin surface, for instance two centimeters persecond. With that action, shear forces of tension and compression areapplied to the skin, with sufficient amplitude to slightly force openthe pores, but low enough to minimize any skin stretching ordeformation. In this embodiment, the peak amplitude of motion isapproximately 39% of the spacing between adjacent contact elements.

At the above-noted frequency range, with a minimum of 20 Hz, each poreopening is deformed approximately 10 times per second. At higherfrequencies, the number of deformations per second would beproportionately greater. Alternating tension and compression stress inthe tissue surrounding the infundibulum results, with the adhesionbetween the sebaceous plug and the infundibular wall being weakened orsignificantly reduced, so that the plug becomes essentially loose in thepore.

While the embodiment of FIGS. 10-12 shows two fixed contact elements andone movable contact element, it should be recognized that only one fixedcontact element could be used, or a plurality of fixed contact elementsand oscillating contact elements can be used to provide a slightly widercoverage. In the case of a plurality of contact elements, the movingmultiple contact element(s) are interdigitated with the fixed contactelement(s), and are driven in a ganged manner.

In addition, both contact elements can be driven, preferably in equaland opposite directions of motion with respect to each other. A peakamplitude of 0.02 inches for each of two moving elements would result ina peak amplitude of relative motion of 0.04 inches.

FIGS. 13A-13D show action on a pore with a sebaceous plug with thetension/compression arrangement of FIGS. 10-12.

FIG. 13A shows a pore 78 blocked by a sebaceous plug 79 therein. Thecontact elements are in a neutral position. The movable contact elementwill then be moved in one direction, perpendicularly away from the fixedelement, which deforms the sebaceous plug and causes deformation of thepore in one direction (FIG. 13B). The motion is then reversed andreturns to the neutral position, relaxing the force between thesebaceous plug and the acroinfundibulum, as shown in FIG. 13C. Themovable contact element will then be moved in the opposite direction,perpendicularly away from the fixed element, which also deforms thesebaceous plug opposite direction (FIG. 13D). This sequence isaccomplished at a frequency within the range of 20-1,000 Hz, andpreferably in the range of 80-200 Hz. Continued action dislodges orreleases the sebaceous plug from the pore walls. The user slowly movesthe device across the surface of the skin, producing the above resultsover an entire skin area.

A further alternate mechanical configuration is shown in FIGS. 15-22.These configurations operate on substantially the same principles as thedevices described above, but have contact elements composed of bristletufts. In these embodiments, the base portions holding the bristle tuftsare analogous to the mounting plates described above. Instead of rigidor compliant solid contact elements, a plurality of bristle tufts areemployed. Each tuft is further composed of a plurality of filaments orbristles. The bristles may be made from any material suitable for theapplication, with the preferred material being Nylon 612. The diameterof each bristle is in the range of 2 to 5 mils with a preferred diameterof 3 mils, and of lengths in the range 0.25 to 0.60 inches, with apreferred length of 0.43 inches in length.

The base of the tuft has a diameter in the range of 40 to 100 mils witha preferred diameter of 60 mils for the tufts of the fixed and movinginterior bristle tuft rows and a preferred diameter of 80 mils for thefixed exterior bristle tuft row. The diameter and length of the bristlesdetermine their stiffness. Using the same material, larger diameterbristles are stiffer than smaller diameter bristles. Generally longerbristles are softer than shorter bristles. The material used to make thebristles also dictates the stiffness character of the bristles.Additionally, the rows can be made with individual tufts having adifferent number of bristles. Generally, having more bristles of asmaller diameter in a tuft will produce a softer sensation.

Tufts of 0.003 inches diameter Nylon 612 bristles 0.43 inches in lengthproduce a lateral stiffness which works well in moving the skin withinRegion I and the lower part of Region II of FIG. 4. Such tufts produce alateral spring constant of approximately 10 grams/inch at a displacementof 0.06″; i.e. a lateral displacement of 0.06″ of the end of a tuftresults when a lateral force of 0.6 grams is applied to the end of thetuft relative to the base.

FIGS. 5-18 show an embodiment using linear motion of the bristle rows.In FIGS. 15-16, both sets of bristle rows (first set of three rows70-70, second set of three rows 72-72) move with respect to each other,while in FIGS. 17-18, one set of four rows 82-82 is fixed and the otherset of three rows 80-80 moves. In both embodiments, the rows ofmoving/fixed bristle tufts are surrounded by a circle of bristle tufts84, the circle of bristles 84 being fixed and functioning like a curtainto keep cleanser/water on the skin.

In another embodiment shown in FIGS. 19-22, the row(s) of bristle tuftsare circular and move in an arcuate manner with the axis of rotationperpendicular to the surface of the skin. FIGS. 19-20 show an embodimentin which both sets of circular bristle rows (two rows 90-90 and two rows92-92) move with respect to each other, while FIGS. 21-22 show anembodiment in which one set of two rows 100-100 moves and the other setof three rows 102-102 is fixed. In each case, one row each of 90 and 92bristle rows and one row each of 100 and 102 bristle rows would likelybe sufficient for cleansing action. Additional rows beyond that showncould also work. In both of these embodiments, the rows of bristles areencircled by a circle of fixed bristles 104, acting as a curtain forliquid, etc. In the embodiment of FIGS. 19 and 20, there is also acircle of fixed bristles 106 inside of the circle of rows 90 and 92.

The adjacent rows of bristle tufts for the devices shown in FIGS. 15-22move relative to each other at an amplitude sufficient to deform theskin in region I and slightly into region II of FIG. 4 as shown toproduce the cleansing action.

FIG. 5A shows the cleansing action of bristles with a single tuft ofbristles 120 against the skin 121 when base 122 is at rest (neutral),while FIG. 5B shows the tuft 120 when the base 122 is at a maximumexcursion. The skin 121 is indicated with “tick” marks on a horizontalline, with the tick spacing showing relative deformation of the skin.

In FIG. 5A, the uniform spacing of the tick marks indicates that thereis no deformation of the skin when the bristles are in the restposition. FIG. 5B shows that the skin has been compressed slightly bythe bristles in the direction of motion of the base, and stretchedslightly behind the tips of the bristles. In typical operation, both thebristles and the skin deform, and there is relatively little slippage ofthe bristles on the skin. As the tuft base moves from its rest (neutral)position, the skin deformation increases, as does its modulus, until therestorative force of the skin just balances that of the bristles.

Typical peak-to-peak amplitudes measured at the base of the bristletufts of 0.05 inches to 0.25 inches can be used with rows havingcenter-to-center spacing of 0.10-0.25 inches. This results in the peakamplitude (50% of peak-to-peak amplitude) of typically 40%, and in arange of 10% to 100% of the center-to-center spacing between adjacentrows of tufts. At high amplitudes, the bristles may also slide acrossthe surface, especially if the brush is used with lubricating elements.

Referring now again to FIGS. 19-22, lubricating fluid can be supplied bythe device, for example, through a central port 106 shown in FIGS. 19and 20. Centripetal force tends to spread the emitted fluid onto thebristles, supplying relatively uniform wetting. The fluid is containedby the bristle curtain 104.

In the case of rotational configurations such as shown in FIGS. 19-22,the linear amplitude of motion is larger for the outer rings. Thecenter-to-center spacing can be adjusted among the rows to maintain anapproximately constant ratio of amplitude to inter-element spacing.

The bristle rows described above can also be replaced with flexiblemembers, such as an elastomer or closed cell foam.

It is also possible to combine the advantages of the differential shearmode and tension/compression modes described above into a compoundmotion, for example, elliptical.

It is also possible to apply bi-directional motion to the skin via asingle set of contact elements for cleaning or clearing the infundibularopening. Unlike the cases above in which there is a differentialreciprocating motion between adjacent contact elements, the use of asingle set of elements relies on inertia of the skin to effect adifferential force on the pore openings. The single set of movingcontact elements, such as a row of bristles, forces the skin immediatelyadjacent to it to move. This movement is coupled to skin regionssomewhat distant through the skin's elasticity. However, skin also hasinertia which resists motion, thereby producing a shear force in thedirection of movement. This shear force decreases at greater distancesfrom the moving contact elements.

Applying bi-directional reciprocating movement via a single set ofcontact elements is generally not as effective as using adjacent contactelements arranged to apply tension/compression or shear between them.

The single set of reciprocating contact elements can be implemented in alinear manner, such as the device of FIGS. 17 and 18, with all linearbristles moving in unison. This single set reciprocating motion can alsobe implemented in an arcuate manner, such as the device of FIGS. 21-22,with all rows of bristles moving in unison. Where the contacting elementcomprises rigid or compliant material, the peak-to-peak amplitude ofmovement will be within the range of 0.04-0.150 inches, preferably 0.09inches; if the contacting element is a row of bristles, the peak-to-peakamplitude of movement is within the range of 0.020 to 0.160 inches,preferably 0.082 inches.

FIG. 23 shows a schematic block diagram for a control means forcontrolling the amplitude of the moving portions of the contact elements120. The control means is composed of a sensing element 121, a powermodulation circuit 122, and a driver circuit 124. The sensing element121 senses the amount of pressure applied to the skin by the contactelements 120 and applies a signal to the power modulation circuit 122.The power modulation circuit 122 uses said signal to modulate the powerof the driver circuit 124 and amplitude of the contact elements 120.

The control means operates in a plurality of operating modes with apreferred number of three operating modes. Proper operation of theapparatus requires that the pressure applied to the skin by theapplicator remains in given range.

When pressure applied by the contact elements to the skin is below thelower threshold for proper operation of the apparatus, the amplitude ofthe applicator with the contact elements is substantially reduced fromits nominal amplitude. This reduces the likelihood of splashing offluids or cleaning agents when the applicator is not in contact with theskin.

When pressure applied by the applicator to the skin is above the lowerthreshold for proper operation of the apparatus, but below the upperthreshold, the applicator is driven at nominal amplitude.

When pressure applied to the skin by the applicator is above the upperthreshold for proper operation the amplitude of the applicator with thecontact elements is substantially reduced from its normal amplitude or,preferably, stopped altogether. An alternative is to interrupt the powerto the contact elements at a low frequency, for example 2-10 Hz, inorder to create an audible or tactile feedback to the user to reduce thepressure. This excess pressure feedback signal reduces the likelihoodthat the applicator will cause too much motion of the skin.

The above-described control means provides not only safety andconvenience, but also provides feedback to the user to maintainapplicator pressure in the range for proper operation of the apparatus.

FIG. 24 shows four regions of the face that differ in topology anddegree of sebaceous secretion. Generally the face is divided into twodistinct regions, the so-called “T-zone” 130 and 132, and the outercheek areas 134, 136. The T-zone is the part of the face consisting ofthe forehead, nose and the area around the mouth, including the chin. Itis so named because it is shaped like the letter T.

Often the T-zone is more prone to acne, as the percentage of sebumglands in this area tends to be higher than on the outer cheeks. Animportant component of the present invention, therefore, is a timermeans to assist the user in properly treating the differing zones of theface, according to the typical incidence of acne in that area, withoutover- or under-treating the area. The total treatment time may be from30 seconds to two minutes and preferably one minute. Further, the totaltime may be subdivided into two or more and preferably four timeperiods. In the present invention, the first time period is 20 secondsfor treatment of the forehead 130; the second time period is 20 secondsfor treatment of the nose, perioral area and chin 132; and 10 secondsfor each outer cheek areas 134, 136.

A timer means 140 (FIG. 25) prompts the user by providing either anaudible signal 142 or a detectable change in the motion of the movingcontacting element, or both simultaneously. This prompt instructs theuser when the preferred treatment time has elapsed for each area of theface. The timer can be enabled or disabled after the apparatus is turnedon, by means of an on/off switch 146 being pressed on for a selectedperiod of time. A first audible signal can be used to indicate that thetimer has been enabled and a second audible signal to indicate that thetimer has been disabled.

In summary, applying differential motion locally to the infundibular(pore) opening results in the clearing of sebaceous plugs from theacroinfundibulum (top of the pore). The differential motion, whetherlinear, arcuate or elliptical, applies forces to the interface betweenthe comedone (sebaceous plug) and the surrounding tissue, thus breakingthe adhesion between the acroinfundibular wall and the sebaceous plug.

A bi-directional, return-to-center motion generally provides bettercleaning than unidirectional motion due to the nature of the sebaceousplug, i.e. the sebaceous plug can be thought of as a generallydisorganized matrix of flat, brick-like corneocytes embedded in a“mortar” of oxidized sebum lipids. Adhesion of the plug to the wall ofthe acroinfundibulum is thought to be caused by a combination ofoxidized sebum and ceramide lipids. Because the orientation of thecorneocytes is not completely random relative to the wall of theacroinfundibulum, it is possible that unidirectional motion alone wouldeliminate some of the adhesion but may be insufficient to loosen thesebum plug. The preferred embodiment of the invention appliesbi-directional motion such that most or all of the corneocytes aresubject to adhesion-breaking stresses irrespective of their orientation.

Limiting the amplitude of bi-directional motion to an extent whichgenerally maintains the skin in a region of low strain is alsobeneficial. High amplitude bi-directional or uni-directional motionplaces the collagen fibers in a higher strain condition.

In use, our invention applies cyclic deformation and relaxation manytimes per second to the skin surrounding the acroinfundibulum and anysebaceous plug. The repetition of differential vibratory cycles suppliesa therapeutic effect by gradually breaking the adhesion between theacroinfundibulum and the sebaceous plug.

The present invention is intended to operate in a frequency range of20-1000 Hz. A preferred range is 80-200 Hz. Below 80 Hz, the vibrationrate is less than optimal and the mechanical implementation is moredifficult. Above 200 Hz, a strong tickle reaction, usually unpleasant,occurs in the nose region. Assuming a 1 cm width of active surface ofthe device operating at the minimum frequency, moving the device acrossthe skin surface linearly at 2 cm/sec would result in each poreexperiencing 10 deformation cycles, many more times than would bepracticable by any manual technique. At higher frequencies the number ofdeformations per stroke of the appliance would be proportionallygreater.

There are two basic modes of differential movement that can be applied:shear and tension/compression. The shear mode device applies a lineardifferential motion via narrow elements which contact the skin, andwhich move in the direction of their length with respect to each other.The device typically applies a sinusoidal oscillation to adjacentcontact elements. The arrangement includes two contact elementassemblies. The device moves the contact elements in parallel to eachother along their long axis. Sufficient functional forces between thesurface of the contact elements and the skin surface will transfer thismotion to the skin, creating a shear action on the skin between them asshown in FIGS. 9A-9D.

The tension/compression mode device, in contrast to shear mode, movesthe contact elements toward and away from each other. The oscillationsare perpendicular to the long axis of the contact elements (i.e. oneelement moving toward one neighbor and away from its other neighbor),thus creating alternating tension and compression stress in the tissuesurrounding the infundibulum. Sufficient frictional forces between thesurface of the contact elements and the skin surface will transfer thismotion to the skin as shown in FIGS. 13A-13D.

Alternatively to one contact element moving, both contact elements maymove with respect to the device body, and counter to one another.

The skin contacting elements can be rigid or flexible. Rigid surfacescan be made from stainless steel and plastic. Flexible contactingsurfaces can include bristles, elastomers and soft compliant foam. Thesurfaces should have sufficient roughness in order to transfer themotion to the skin without slippage, or minimizing such slippage.Additionally, the proper degree of surface roughness assures goodlamellar action (transfer of lubricant from wet to dry portion of skinby interstitial spaces in the contacting surface). If the surface finishis too smooth the lubrication is wiped off and the contacting surfaceruns dry against skin and may cause unwanted abrasion of the skin. Thissurface roughness can be in the range of 5 to 20 micro-inches andpreferably is 10 micro-inches.

Multiple contacting elements can be included, such that a set of skincontacting elements moving in one direction are interdigitated between aset of stationary skin contacting elements, or skin contacting elementsmoving in the opposing direction. FIG. 15 shows a device with a doublepair of skin contacting elements, and is a derivative of the device witha single pair of skin contacting elements shown in FIG. 6. In the caseshown in FIG. 15, each of two sets of skin contacting elements consistsof three rows of bristle tufts. Each set of bristle tuft rows moves inrelative opposition, surrounded by a fixed circular row of fixed bristletufts, which serve to minimize splashing and to control the contact ofthe moving bristle tips onto the skin. The bristle tufts are designed sothat the interdigitated row movement results in sufficient force on theskin to maintain acroinfundibular openings. This action is similar tofingers of left and right hands interlocking while hand washing.

The model shown has three rows of bristles in each of the twointerdigitated sets, but the number of bristle rows could vary from asingle row to as many as practical for the desired surface area.

Additionally, the motion of the bristle tuft row(s) can be linear,arcuate or elliptical along the plane of the skin with the axis ofrotation perpendicular to the skin.

The magnitude of reciprocal force applied to the skin is primarilydetermined by the stiffness of bristle tufts to lateral deformation, thelength and width of the bristle rows, spacing between bristle rows,amplitude of interdigitated motion, and the pressure applied by theuser.

The effects on the skin by the movement of the contacting elements canalso be modified with the use of a skin lubricant. The lubricant can bewater, soapy water, another skin cleaning agent, a lotion or gel. Morelubrication results in more sliding action of the bristle tips acrossthe skin, and less deforming action applied to the skin. The slidingaction across the skin serves to remove skin surface debris. The debrisincludes sebum, triglycerides and fatty acids, desquamatized corneocytesand accumulated dirt and environmental materials.

Thus, the present invention provides either mechanical energy in a shearmode or tension/compression mode or a combination (elliptical) in orderto loosen the adhesion between the sebaceous plug and the walls of thepore. Said motion can be produced by contact elements moving eitherreciprocally linearly, reciprocally arcuately or a combination thereof.The loosened sebaceous plug and any previously blocked lipids from thepores can then be readily removed by rinsing the cleansed area. Such anarrangement results in an effective treatment of early stage acne thatprevents the development of more serious acne conditions. In addition,however, the arrangement can be used for effective cleansing of skinwhen acne is not present. The combination of gentleness and cleansingaction produces a desirable, effective cleansing effect on the skin anda “sense” or feel by the user of clean, healthy skin.

Although the preferred embodiments of the invention has been disclosedfor purposes of illustration, it should be understood that varioussubstitutions and changes may be made in such embodiment, withoutdeparting from the spirit of the which is defined by the claims outlinedbelow.

What is claimed is:
 1. A method for cleansing of skin, comprising thesteps of: a first step of deforming the skin from a neutral position toa first deformed position at which point the skin is within its elasticlimit; a second step permitting the skin to return to said neutralposition; and repeating the first and second steps within a frequencyrange of 20 Hz to 1 KHz, to produce an action on the skin which resultsin the cleansing of the skin, wherein the step of deforming the skin isaccomplished by bristles arranged into a plurality of bristle tufts, andwherein the peak amplitude of motion at the base of one bristle tuftwith respect to that of an adjacent bristle tuft is in the range of10%-125% of the center-to-center distance between adjacent bristle tuftsmoving with respect to each other.
 2. The method of claim 1, wherein thecleansing of the skin includes removal of undesired material from skinpores, the undesired material being a sebum plug.
 3. The method of claim1, wherein the frequency range is 80-200 Hz.
 4. The method of claim 1,including a third step of stretching the skin to a second deformedposition in a direction opposite to that in the first step, and a fourthstep of permitting the skin to return to said neutral position, thethird and fourth steps being accomplished prior to the step ofrepeating.
 5. The method of claim 4, wherein the steps of deforming areaccomplished by positively moving the skin.
 6. The method of claim 1,wherein the deformation of the skin is accomplished by a strain action.7. The method of claim 1, wherein the deformation of the skin isaccomplished by a tension/compression action.
 8. The method of claim 1,including a step of applying a fluid to the skin to assist in thecleansing thereof.
 9. The method of claim 1, wherein the steps of themethod are carried out for predetermined times for specific skin areason the face of a user.
 10. The method of claim 1, wherein the bristletufts have a reciprocally arcuate movement.
 11. The method of claim 1,wherein the bristle tufts have a reciprocally linear movement.
 12. Amethod for cleansing of skin, comprising the steps of: repetitivelydeforming skin in one direction to a first position and then in anotherdirection to a second position, wherein the skin returns to a neutralposition between the first and second positions, wherein the step ofdeforming the skin is accomplished by bristles arranged into a pluralityof bristle tufts, and wherein the peak amplitude of motion at the baseof one bristle tuft with respect to that of an adjacent bristle tuft isin the range of 10%-125% of the center-to-center distance betweenadjacent bristle tufts moving with respect to each other, to produce anaction on the skin which results in cleansing of the skin.
 13. Themethod of claim 12, wherein the skin is deformed to within its elasticlimit at the first and second positions.
 14. The method of claim 12,wherein the first and second positions approximately oppose each other.15. The method of claim 12, wherein the step of deforming the skin isaccomplished at a frequency in the range of 20 Hz to 1 KHz.
 16. Themethod of claim 15, wherein the frequency range is 80-200 Hz.
 17. Themethod of claim 12, wherein the cleansing of skin includes removal ofundesired material from skin pores, including sebum plugs.
 18. Themethod of claim 12, wherein the step of deforming the skin isaccomplished by a strain action.
 19. The method of claim 12, wherein thestep of deforming the skin is accomplished by a tension/compressionaction.
 20. The method of claim 12, including the step of applying fluidto the skin to assist in the cleansing thereof.
 21. The method of claim12, wherein the steps of the method are carried out for predeterminedtimes for specific skin areas on the face of a user.
 22. The method ofclaim 12, wherein the step of deforming the skin is accomplished by abrush member, comprising circular rows of bristle tufts, wherein thebristle tufts move in a reciprocally arcuate manner.
 23. The method ofclaim 12, wherein the step of deforming the skin is accomplished by abrush member, comprising straight rows of bristle tufts, wherein thebristle tufts move in a reciprocally linear manner.
 24. The method ofclaim 12, wherein the step of deforming is accomplished by positivelymoving the skin in said one direction and then in said anotherdirection.